The invention relates generally to a pipe connection arrangement such as that required for a water tank of a heat exchanger of a motor vehicle heater. In particular, a preferred embodiment of the pipe arrangement includes an insertable pipe end that is equipped with a sealing means. The pipe end is tightly inserted into an opening of a connecting sleeve and held in this position by means of a U-shaped clamp. The legs of the clamp are guided through passage openings in the connecting sleeve and rest against a collar of the pipe end.
In German Published Unexamined patent application DE-OS No. 31 26 405, a pipe connection is described having the form of an insertion coupling for hydraulic high-pressure piping. In this connection, two collar-type shoulders respectively are assigned to the pipe end that form a groove between one another. Legs of a U-shaped clamp having a square cross-section engage in this groove for securing the coupled position. The pipe is sealed in the connecting sleeve by means of an O-ring which is held in a groove at the free end of the pipe and rests against a corresponding sealing area of the connecting sleeve. This construction involves an insertion coupling in which the U-shaped clamp must take over the securing of the position also with respect to a possible excess pressure occuring on the inside of the connecting sleeve. In order to keep the surface pressure between a shoulder and the legs of the clamp as low as possible, the clamp has a square cross-section that is adapted to the size of the groove between the shoulders. A disadvantage of this construction is the relatively high expenditures which are required for the manufacturing of an insertion nipple at the end of the pipe. Additionally, the free end of one of the legs of the adapted clamp must be equipped with a safety hook directed toward the outside for the securing of its position.
It is, therefore, an object of this invention to provide a pipe connection having a contact area between a clamp and a collar of a pipe which is as large as possible.
It is another object of this invention to provide a pipe connection having a simple design.
The above and other objects are attained by a pipe connection arrangement including an insertable pipe having a sealing means arranged near one end of the pipe. The pipe includes a collar having a radius (r) and is inserted into a connecting sleeve having a receiving bore therein. The sleeve includes a passage opening formed as at least one slot on the side of the pipe. The arrangement is secured by a clamp shaped in a preferred embodiment as a U-shaped clamp, and includes two legs which are extendable through the slot of the sleeve. The width of the slot corresponds to the external spacing of the legs of the clamp. Additionally, the interior radius of the U-shaped bracket part of the clamp is adapted to correspond to the interior radius (r) of the collar and outer diameter of the pipe. As a result of the invention, the clamp rests against the collar over more than half of its circumference and, therefore, is subjected to a largely even contact pressure. This is very advantageous, especially when the sealing means rests against the collar on the side facing away from the clamp and is pressed into a recess at the connecting sleeve. One resulting effect is a rattle-free fitting of the pipe in the connecting sleeve because the sealing means takes over a double function. This type of fitting arrangement is especially important for use in motor vehicles where, because of the vibrations caused during the driving, a rattle-free fitting is required. The new pipe connection is, therefore, especially suitable for the connecting of the feed pipes to the water tanks of motor vehicle heat exchangers, particularly for motor vehicle heaters. The new pipe connection can also be used in a relatively simple way for connecting sleeves of water tanks made of plastic. Another advantageous feature of the present invention is that the clamp can be inserted into the slot from either side of the pipe, thereby simplifying assembly of the arrangement.
An especially preferred embodiment includes the advantageous feature of providing a gripping clip in the center area of the U-shaped bracket part of the clamp. This clip facilitates the mounting and dismounting of the clamp such that, in an installed condition, the bracket part is pushed into the connecting sleeve. In a particularly simple way, the gripping clip may be developed as another U-shaped clamp which is in alignment with the first U-shaped clamp, the legs of the gripping U-shaped clamp being mounted at the bracket part of the first clamp. This additional gripping clamp can be formed out of the material of the first clamp as a single piece. In this embodiment, it is also advantageous for the slot in the connecting sleeve to include in its center, a reinforcing web extending vertically to the plane of the slot. The reinforcing web grips between the legs of the additional gripping clamp and can serve as a snap-on element for the clamp which has a corresponding narrowing, thereby securing the clamp in its end position.
In especially preferred embodiments, as depicted in the drawings, the conformance of the legs and bracket part of the clamp extend substantially over the circumference of the pipe adjacent to the collar in order to provide a simple and secured connection. Preferably, between 90.degree. to 180.degree. of the inner circumference of the collar is adjacent with the U-shape clamp.
Further objects, features, and advantages of the present invention will become more apparent from the following description when taken with the accompanying drawings which show, for purposes of illustration only, an embodiment in accordance with the present invention.